Add FishNet network library

Assets/FishNet/Runtime/Managing/NetworkManager.Pro.cs

@@ -0,0 +1,15 @@
+using FishNet.Component.ColliderRollback;
+using UnityEngine;
+
+namespace FishNet.Managing
+{
+    public sealed partial class NetworkManager : MonoBehaviour
+    {
+        #region Public.
+        /// <summary>
+        /// RollbackManager for this NetworkManager.
+        /// </summary>
+        public RollbackManager RollbackManager { get; private set; }
+        #endregion
+    }
+}